1. Field of the Invention
This invention relates generally to data encryption and cryptographic methods.
2. Description of the Related Art
In current practice of data encryption and key generation which is based on mathematical properties of classical data, there is no information theoretic security (ITS) under known-plaintext attacks (KPA) by an adversary Eve, or even just for raw security before the generated key K is used in public key systems. Instead, security is based on the computational complexity of obtaining the correct answer on a mathematical problem related to the cryptographic protocol employed. Such complexity-based security (CBS) may be insecure against future development of computational power and algorithms, and improvement on such security predicament is sought for a variety of applications.
New development in physical cryptography that utilizes either classical noise or quantum effect show some promise of obtaining ITS but is beset with fundamental security issues and efficiency problems. In particular, there are serious efficiency and security issues in connection with the quantum key distribution (QKD) protocol BB84. The KCQ (keyed communication in quantum noise) approach has been experimentally developed to a less extent, and generally security proof is yet to be obtained. A most serious difficulty for such proof in both QKD and KCQ is the correlations between bits in the cryptosystem, as it is in classical and conventional mathematical cryptography.
Therefore, there is a need for cryptographic methods that yield quantifiable general security for almost any classical or quantum protocol of data encryption and key generation.